The invention relates to a turbine blade of a gas turbine comprising at least one cooling air duct extending in the blade as well as a shroud band segment which is arranged on the blade tip and which, together with additional segments of adjacent blades, forms a blade reinforcing band, a cooling air branch duct is provided which extends in the shroud band segment essentially perpendicularly to the blade axis, is connected with the blade cooling air duct situated in the leading area of the blade and from which cooling air bores lead to the surface of the shroud band segment.
Such a cooled gas turbine blade is shown in German Patent Document 39 30 324 A1. By means of this type of a cooling of not only the blade but also of the shroud band segment, it can be achieved and the thermal stress and the geometrical deformations can be kept low to which the blade and the segment are subjected as a result of thermal influences. Although the thermal stress to a turbine blade is already considerably reduced by means of the known cooling air guiding, additional improved cooling measures are desirable which are the object of the present invention.